Methods for forming ethylbenzene from polystyrene

ABSTRACT

According to one or more embodiments presently disclosed, a method of catalytically converting polystyrene may include contacting polystyrene with a catalyst to form a product comprising ethylbenzene. The catalyst may include oxidized iron, oxidized cobalt, and oxidized copper. The catalyst may further include a mesoporous support material with pores having an average pore diameter of from 2 nm to 50 nm.

CROSS REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to U.S. Provisional patentapplication Ser. No. 62/711,861 entitled “METHODS FOR FORMINGETHYLBENZENE FROM POLYSTYRENE,” the entirety of which is incorporated byreference in the present disclosure.

BACKGROUND Field

The present disclosure generally relates to catalysts and, morespecifically, to supported, metallic catalysts and methods for theproduction thereof.

Technical Background

Various chemical processes are facilitated by catalysts. For example,catalysts may be utilized in cracking reactions which breakcarbon-carbon bonds to form new, smaller molecules. Such crackingreactions may chemically convert substances such as polymers intosmaller polymeric or even monomeric units.

BRIEF SUMMARY

Accordingly, there is a need for catalysts which may be useful invarious chemical processes such as the conversion of polystyrene. Theconversion of polystyrene to ethylbenzene may be useful in polymerrecycling. According to one or more embodiments presently described,supported catalysts that include iron, cobalt, and copper may beeffective catalysts for processes such as the cracking of polystyrene.The presently described catalysts may convert polystyrene with goodselectivity for ethylbenzene formation as compared with other knowncatalysts. Additionally, such yields of ethylbenzene may be realized atrelatively low reaction temperatures (such as, for example 250° C.).Such catalytic activity may allow for efficient recycling of polystyreneinto a product including 90 wt. % liquid components at a processingtemperature of only 250° C. Other known catalysts may require greaterreaction temperatures, such as at least 350° C. and not even achieve asgreat of liquid yields.

According to one or more embodiments presently described, the catalystsmay not only increase reaction rates as compared with conventionalcatalysts, but may also improve selectivity towards desired products.For example, the presently described catalysts may crack polystyrenewith enhanced yields of ethylbenzene as compared to yields of otherformed products such as styrene, toluene, or dimers.

In one or more embodiments, the presently described catalysts may besupported on a mesoporous support material and include iron, cobalt, andcopper. The iron, cobalt, and copper may be present in the catalyst asoxidized metals (either as compounds that include only one particularmetal oxide, or as compounds that include a plurality of metals in anoxidized form). It is believed that the presently disclosed multi-metalcatalysts may have favorable catalytic performance as compared withconventional catalysts which contain only one or two metals ascatalysts. Such presently described multi-metal catalysts may allow forfine tuning of interaction energies for a particular reaction and mayprovide multiple catalytic centers for different reaction steps. Theseproperties may offer the presently disclosed multi-metallic catalyst thebenefit of cracking with higher efficiencies and product selectivity,even at lower temperatures.

According to one or more additional embodiments, a method ofcatalytically converting polystyrene may comprise contacting a feedstream comprising polystyrene with a catalyst to form a product streamcomprising ethylbenzene. The catalyst may comprise oxidized iron,oxidized cobalt, and oxidized copper. The catalyst may further comprisea mesoporous support material comprising pores having an average porediameter of from 2 nm to 50 nm.

Although the concepts of the present disclosure are presently described,in one or more embodiments, with primary reference to cracking catalystsfor the cracking of petrochemical products such as heavy oils orpolystyrenes, it is contemplated that the presently disclosed conceptswill enjoy applicability to other catalytic functionality. For example,and not by way of limitation, it is contemplated that the concepts ofthe present disclosure will enjoy applicability to other catalyticcracking processes which may benefit from the breaking of carbon-carbonbonds.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent disclosure can be best understood when read in conjunction withthe following drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 is a generalized flow chart showing synthesis steps for asupported metallic catalyst, according to one or more embodimentspresently disclosed;

FIG. 2A is a graph showing the adsorption/desorption behavior ofnitrogen on one embodiment of the presently disclosed catalyst and itssupport material;

FIG. 2B is a graph showing the pore size distribution of one embodimentof the presently disclosed catalyst and its support material;

FIG. 3A is a graph showing the carbon dioxide (CO₂) temperatureprogrammed desorption (TPD) behavior of one embodiment of the presentlydisclosed catalyst and its support material;

FIG. 3B is a graph showing the ammonia (NH₃) temperature programmeddesorption behavior of one embodiment of the presently disclosedcatalyst and its support material;

FIG. 4A provides the x-ray diffraction (XRD) pattern of one embodimentof the presently disclosed mesoporous support material;

FIG. 4B provides the x-ray diffraction pattern of one embodiment of thepresently disclosed catalyst;

FIG. 5A is a graph showing the influence of catalyst loading on theratio of liquid to solid yields for the catalytic cracking ofpolystyrene by the presently disclosed catalyst;

FIG. 5B is a graph showing the influence of catalyst loading on theratio of different liquid products for the catalytic cracking ofpolystyrene by the presently disclosed catalyst;

FIG. 6A is a scanning electron microscope (SEM) image of one embodimentof the presently disclosed catalyst;

FIG. 6B is a scanning electron microscope image of one embodiment of thepresently disclosed catalyst, after the catalyst has been used tocatalytically crack polystyrene;

FIG. 7A is a scanning transmission electron microscope (STEM) image ofone embodiment of the presently disclosed catalyst;

FIG. 7B is a scanning transmission electron microscope image of oneembodiment of the presently disclosed catalyst, after the catalyst hasbeen used to catalytically crack polystyrene;

FIG. 8A is a graph depicting scanning transmission electronmicroscope-energy dispersive spectroscopy of one embodiment thepresently disclosed catalyst;

FIG. 8B is a graph depicting scanning transmission electronmicroscope-energy dispersive spectroscopy (STEM-EDS) of one embodimentof the presently disclosed catalyst, after the catalyst has been used tocatalytically crack polystyrene;

FIG. 8C is a graph depicting scanning transmission electronmicroscope-electron energy loss spectroscopy (STEM-EELS) of oneembodiment of the presently disclosed catalyst; and

FIG. 8D is a graph depicting scanning transmission electronmicroscope-electron energy loss spectroscopy of one embodiment of thepresently disclosed catalyst, after the catalyst has been used tocatalytically crack polystyrene.

DETAILED DESCRIPTION

The following detailed description describes one or more embodiments ofthe presently disclosed catalysts. One or more embodiments of thepresent disclosure are directed to catalysts which may comprisecatalytic oxidized metal materials including oxidized iron, oxidizedcobalt, and oxidized copper. In some embodiments, the oxidized iron,oxidized cobalt, and oxidized copper may comprise the majority, or all,or the catalytic oxidized metal material in the catalyst. In one or moreembodiments, the catalyst may further include a mesoporous supportmaterial (sometimes referred to as a “support”) comprising pores havingan average pore diameter of from 2 nm to 50 nm. Additional embodimentsinclude methods for making such catalysts. The catalysts presentlydisclosed may be multi-metallic catalysts which include at least threedifferent metals.

Without being limited by theory, it is believed that multi-metalliccatalysts having at least three metal compounds differ from monometallicor bimetallic catalysts in structural effects, electronic properties, orboth. These properties may, in some cases, present advantages overmono-metallic or bimetallic catalysts in activity, selectivity, or both.

It should be understood that the metals in the multi-metallic catalystsneed not be present in their metallic form (that is, as a pure metal).For example, they may be present in their oxide form or in compoundswith different metal atoms. For example, iron may be present as Fe₂O₃ inthe catalysts, or in an oxide compound that includes iron as well as oneor more additional metals such as cobalt or copper. Without beinglimited by theory, it is believed that the choice of metals, theirratios to one another, the choice of catalyst support material, or anycombination of these, may play a significant role in the effectivenessof a catalyst.

The presently disclosed catalyst may include catalytic oxidized metalmaterials comprising at least three oxidized metals (that is, oxidizediron, oxidized cobalt, and oxidized copper). As presently described, an“oxidized metal” may refer to any oxidized elemental metal (such asiron, cobalt, or copper) that is in a chemical compound, such as a metaloxide that includes one or more elemental metals. As such, the oxidizedmetals of the catalyst may be included in one or more differentcompounds, where more than one metal oxide is in the same compound. Forexample, a chemical compound that includes one or more of the oxidizedmetals, as presently described, may include a single elemental metal inan oxidized state (that is, a single oxidized metal), or mayalternatively include multiple elemental metals each in oxidized states(that is, a compound that includes at least two or more elemental metalsand oxygen). Elemental metals, as described presently, refer to anymetal or metalloid elements of the periodic table. It should beunderstood that oxidized metals may be present in any oxidation state.The disclosed oxidized metals, such as oxidized iron, oxidized cobalt,and oxidized copper may be in different compounds or all included in asingle compound.

According to one or more embodiments, the catalytic oxidized metalmaterials may comprise at least three metal oxide compounds, where theoxidized iron, the oxidized cobalt, and the oxidized copper are presentin separate metal oxide compounds. For example, the catalytic oxidizedmetal materials may comprise iron oxide, cobalt oxide, and copper oxide.In one or more embodiments, the catalyst may include, withoutlimitation, one or more of iron (II) oxide (FeO), iron (IV) oxide(FeO₂), iron (II, III) oxide (Fe₃O₄), iron (II, III) oxide (Fe₅O₆), iron(II, III) oxide (Fe₅O₇, Fe₂₅O₃₂, or Fe₁₃O₁₉), or iron (III) oxide(Fe₂O₃). The catalyst may further include, without limitation, one ormore of cobalt (II,III) oxide (Co₃O₄), cobalt (II) oxide (CoO), orcobalt (III) oxide (Co₂O₃). Without limitation, the catalyst may includeone or more of copper (II) oxide (CuO), copper (IV) oxide (CuO₂, orCu₂O), or copper (III) oxide (Cu₂O₃).

According to some embodiments, at least 95 wt. % of the catalyticoxidized metal materials may be a combination of oxidized iron, oxidizedcobalt, and oxidized copper. The weight percent is to be calculated onthe basis of all metals in the catalyst, excluding those which arecharacterized as the support material. Generally, these metallicmaterials contribute to the catalytic functionality of the catalyst andare disposed on the support material. In one or more embodiments, atleast 96 wt. %, at least 97 wt. %, at least 98 wt. %, at least 99 wt. %,at least 99.5 wt. %, or even at least 99.9 wt. %, of the catalyticoxidized metal materials may be a combination of oxidized iron, oxidizedcobalt, and oxidized copper. In further embodiments, the catalyticoxidized metal materials may consist essentially of or consist ofoxidized iron, oxidized copper, and oxidized cobalt.

According to additional embodiments, the catalytic oxidized metalmaterials may include any combination of oxidized iron, oxidized cobalt,and oxidized copper in a single compound. For example, the catalyticoxidized metal materials may include a compound formed by any of theiron oxides, cobalt oxides, or copper oxides presently disclosed.Embodiments are contemplated where oxidized iron and oxidized cobalt arepresent in a single compound, where oxidized iron and oxidized copperare present in a single compound, or where oxidized cobalt and oxidizediron are present in a single compound. Additional embodiments mayinclude a catalyst that comprises a chemical compound that includesoxidized iron, oxidized cobalt, and oxidized copper. For example, andwithout limitation, iron cobalt oxide (Fe₂CoO₄) and copper cobalt oxide(CuCoO₂) may be included in the catalyst. In one or more embodiments,the majority of the oxidized iron, oxidized cobalt, an oxidized coppermay be present in the form of Fe₂O₃, Cu₂O, CuO, and Co₃O₄.

In one or more embodiments, the weight ratio of iron atoms:cobaltatoms:copper atoms in the catalyst may be from 1:0.4-0.6:0.5-0.7. Forexample, in one or more embodiments, the weight ratio of ironatoms:cobalt atoms in the catalyst may be from 1:0.4 to 1:0.42, from1:0.42 to 1:0.44, from 1:0.44 to 1:0.46, from 1:0.46 to 1:0.48, from1:0.48 to 1:0.5, from 1:0.5 to 1:0.52, from 1:0.52 to 1:0.54, from1:0.54 to 1:0.56, from 1:0.56 to 1:0.58, from 1:0.58 to 1:0.6, or anycombination thereof. For example, in one or more embodiments, the weightratio of iron atoms:copper atoms in the catalyst may be from 1:0.50 to1:0.52, 1:0.52 to 1:0.54, from 1:0.54 to 1:0.56, from 1:0.56 to 1:0.58,from 1:0.58 to 1:0.6, from 1:0.6 to 1:0.62, from 1:0.62 to 1:0.64, from1:0.64 to 1:0.68, from 1:0.68 to 1:0.70, or any combination thereof. Itshould be understood that ranges are contemplated that include multiplesub-ranges presently disclosed. It should be understood that when aratio of three components is disclosed, that any two of those componentsare contemplated to have a defined ratio as presently described.

Without being bound by theory, it is believed that when at least somereactions take place on a supported catalyst, properties of the catalystsupport material may affect the reaction. For example, properties of thecatalyst support material that may affect catalytic functionalityinclude one or more of the solubility of the support in relevantsolvents, the surface area of the support, the pore size of the support,and the acidity of the support.

According to one or more embodiments, the catalyst support may bemesoporous. Without being bound by any particular theory, anothercharacteristic of a catalytic support that may affect catalyticperformance may be the pore size. Porous materials can be defined asmicroporous materials, mesoporous materials, and macroporous materials.Microporous materials have pore diameters less than 2 nm, mesoporousmaterials have pore diameters from 2 nm to 50 nm, and macroporousmaterials have pore diameters of greater than 50 nm. In this applicationthe categories microporous, mesoporous, and macroporous are all used torefer to the average pore diameter because the diameter of eachindividual pore will vary. Because some materials may have clusters ofaverage sizes or be hierarchical with vastly different pore structures,it is possible for one material to have multiple pore diametercharacterizations. For example, an activated carbon may be mesoporous,microporous, or both, depending on the synthesis method.

While pore size may have an effect on surface area, in a catalyst, poresize also may help to affect which reagents can reach the catalyticcenters located within the pores. Therefore, without being limited bytheory, it is believed that catalyst pore size may affect both activityand selectivity. The presently described catalysts may includemesoporous support materials such as one or more of silica, alumina,alumosilicates, or activated carbon.

According to one or more embodiments, the surface area of the catalystmay be greater than or equal to 100 square meters per gram (m²/g). Forexample, surface area of the catalyst may be greater than or equal to125 m²/g, greater than or equal to 150 m²/g, greater than or equal to175 m²/g, greater than or equal to 200 m²/g, greater than or equal to225 m²/g, or even greater than or equal to 250 m²/g. The surface area ofthe catalyst may majorly be a function of the support material. Thesurface area of a catalyst support material may be significant fordetermining the utilization ratio of the catalyst bonded to the supportsurface. Without being limited by theory, it is believed that onlycatalytic centers which are accessible by reagents can participate inthe reaction and, therefore, catalytic centers inaccessible by reagentsare essentially wasted. By providing a relatively great surface areasupport, it is believed that smaller catalyst particles with arelatively greater surface area/volume ratio may be used. Surface areaof a support is traditionally described in units of surface area tomass, such as m²/g or surface area to volume, such as square meters percubic meters (m²/m³). Determining the actual surface area of a catalystsupport material is often performed by a molecular adsorption test suchas the Brunauer-Emmett-Teller (BET) surface area measurement.

According to one or more embodiments, the surface area of the mesoporoussupport material may be less than or equal to 700 square meters per gram(m²/g). It has been unexpectedly found that lower surface areamesoporous support material may lead to increased production of liquidproducts in, for example, reactions involving the cracking ofpolystyrene or petroleum tar. Without being limited by theory, it isbelieved that larger surface area mesoporous support materialspreferentially favor oligomerization pathways. This preference foroligomerization pathways may prevent the production of valuable liquidproducts. For example, surface area of the mesoporous support materialmay be less than or equal to 600 m²/g, less than or equal to 500 m²/g,less than or equal to 450 m²/g, less than or equal to 400 m²/g, lessthan or equal to 350 m²/g, less than or equal to 300 m²/g, less than orequal to 250 m²/g, less than or equal to 200 m²/g, less than or equal to150 m²/g, less than or equal to 100 m²/g, or even less than or equal to50 m²/g.

According to one or more embodiments, the catalyst, the support, orboth, may be insoluble in any liquids present during the reaction.Immiscibility of the catalyst support in the relevant solvent may ensurethe heterogeneity of a catalytic reaction. Heterogeneous catalyticreactions may be desired over homogenous catalytic reactions due to theease of separation of products and catalyst. A heterogeneous catalyticreaction is defined in this disclosure as one in which the catalyst andat least some of the products are in different phases. For example, thereaction of a solid phase catalyst with a solid phase reactant and atleast one liquid or gas phase product, is referred to as heterogeneous.

According to one or more embodiments, the mesoporous support materialmay comprise alumina material, such as gamma alumina. As used in thisdisclosure, “alumina material,” also sometimes referred to as “aluminumoxide” or “alumina” in the present disclosure, is a category ofmaterials sharing the chemical formula Al₂O₃. Alumina material, in oneor more embodiments, may be a suitable catalyst support due to one ormore of its amphoteric nature, relatively great surface area, relativelylesser cost, relatively great thermal conductivity, insolubility inaqueous solvents, or mesoporous structure. Alumina material can beformed into a variety of structures including, but without limitation,alumina, alpha alumina, beta alumina, gamma alumina, and theta alumina.Alpha alumina is believed to have a relatively lesser surface area andlittle to no catalytic activity. Beta alumina is believed to behexagonal with somewhat greater surface area. In one or moreembodiments, gamma alumina may be the most desirable phase for use incatalysts due to one or more of its relatively great specific surfacearea, relatively great activity, good temperature resistance, andmesoporosity. According to one or more embodiments, the catalyst may bethermally stable to a temperature greater than 500° C., such as greaterthan 750 degrees Celsius (° C.), greater than 1000° C., or even greaterthan 1500° C.

In one or more embodiments, the support material may comprise at least95 weight percent (wt. %), at least 96 wt. %, at least 97 wt. %, atleast 98 wt. %, at least 99 wt. %, at least 99.5 wt. %, at least 99.9wt. % of alumina, or even consist of alumina. Without being limited bytheory, it is believed that for some reactions, such as those describedpresently, alumina has a good surface acidity level, which can produceliquid products from polystyrene or petroleum tars. It is furtherbelieved that aluminum/silica hybrids (referred to as aluminosilicatesand aluminum silicate) have elevated surface acidity levels relative topure alumina. Therefore, when the support material comprises relativelygreat amounts of aluminum/silica hybrid (for example, greater than 5 wt.%, 10 wt. %, or 25 wt. %), it tends to favor crosslinking reactions andprevent the production of liquid products.

In additional embodiments, the support material may comprise at least 50wt. %, at least 75 wt. %, at least 95 wt. %, or even at least 99 wt. %of gamma alumina.

According to one or more embodiments, the mesoporous support materialmay comprise silica material. As used in this disclosure, silicamaterial, also referred to sometimes in this disclosure as “silica” or“silicon dioxide,” is a category of materials sharing the chemicalformula SiO₂. In some catalytic reactions, silica material may presentan advantage over alumina material due to the absence of acidic sites.Pure silica materials may be present as alpha-quartz, beta-quartz,alpha-tridymite, beta tridymite, alpha-cristobalite, beta-cristobalite,2 dimensional silica sheets, and many other structures. In one or moreembodiments, the support material may comprise at least 50 wt. %, atleast 75 wt. %, at least 95 wt. %, or even at least 99 wt. % of silicamaterial.

In one or more additional embodiments, the catalyst may comprise ahierarchical structured material comprising a silicate oraluminosilicate. For example, the catalysts may be supported on MobilComposition of Matter number 41 (MCM-41). Mixed alumina-silicamaterials, referred to as aluminosilicates, present some of theadvantages of both alumina and silica materials. These mixed materialsmay also be formed in to a material with a hierarchical structure, suchas MCM-41. As used in this disclosure, MCM-41 refers to a family ofmesoporous silica or aluminosilicates materials with a specifichierarchical structure. Without being limited by theory it is believedthat, unlike zeolites, MCM-41 has no Bronstead acid centers and itsacidity is comparable to that of amorphous aluminosilicates. Thisacidity comparable to amorphous aluminosilicates makes MCM-41 a suitablesupport for reactions where crosslinking of polymers is undesirable.

In one or more embodiments, the support material may comprise at least50 wt. %, at least 75 wt. %, at least 95 wt. %, or even at least 99 wt.% of one or more hierarchical structured materials, such a hierarchicalstructures aluminosilicates. In additional embodiments, the supportmaterial may comprise at least 50 wt. %, at least 75 wt. %, at least 95wt. %, or even at least 99 wt. % of MCM-41.

In one or more additional embodiments, the catalyst support may compriseactivated carbon. Generally, activated carbon is a form of carbonprocessed to have increased porosity which causes an increased surfacearea. Activated carbon may have pores of one or more diameters based onthe processing conditions by which it may be produced. It may also havebeen further activated through chemical modifications to its surface.Activated carbon may present an inexpensive, relatively great surfacearea catalyst support with tunable pore sizes. In one or moreembodiments, the support material may comprise at least 50 wt. %, atleast 75 wt. %, at least 95 wt. %, or even at least 99 wt. % ofactivated carbon.

In one or more embodiments, the catalyst support material may besubstantially free of zeolites. One common class of catalyst supportmaterials is the zeolite. Zeolites tend to have a relatively greatacidity and a microporous structure. This greater acidity can negativelyaffect some reactions. For example, it is believed that the greateracidity of a zeolite may cause crosslinking reactions when a polystyreneis present. These crosslinking reactions may inhibit the degradation ofthe polystyrene. Without being limited by theory, it is believed thatmicropores, such as the pores on a zeolite, may be of insufficient sizesuch that they may be blocked by certain reagents such as a polystyreneside group.

According to one or more embodiments, the catalyst may be substantiallyfree of carbon nanotubes. Generally, carbon nanotubes are a form ofcarbon processed into a cylindrical nanostructure. They may take formsincluding single wall (SWNT) and multi wall (MWNT), with diametersranging from 0.3 nm to 100 nm. The carbon nanotube structures are nottruly porous but are more similar to a graphene sheet formed into atube. Without being limited by theory, it is believed that due to theirstructure, carbon nanotubes can have extreme surface area to massratios. It is believed that carbon nanotubes may present challenges incatalytic situations due to their tendency towards agglomeration and thepossibility that reaction products may block entry into the tube sectionof carbon nanotubes.

According to one or more embodiments, the combined weight of iron atoms,cobalt atoms, and copper atoms in the catalyst may be from 0.1 percent(%) to 20% of total weight of the catalyst. The ratio of activecatalytic metal material to catalyst support materials may have asubstantial effect on both catalytic activity and cost. Generally,catalyst support materials are less expensive than active catalyticmetal materials. Due to this cost differential, it may be desirable tominimize the loading of active catalytic metal materials to the extentthis may be possible without affecting activity or selectivity. Forexample, in one or more embodiments, a combined weight of the ironatoms, cobalt atoms, and copper atoms in the catalyst may be from 0.001%to 0.01%, from 0.01% to 0.1%, from 0.1% to 0.5%, from 0.5% to 1%, from1% to 2%, from 2% to 3%, from 3% to 4%, from 4% to 5%, from 5% to 6%,from 6% to 7%, from 7% to 8%, from 8% to 9%, from 9% to 10%, from 10% to11%, from 11% to 12%, from 12% to 13%, from 13% to 14%, from 14% to 15%,from 15% to 16%, from 16% to 17%, from 17% to 18%, from 18% to 19%, from19% to 20%, or any combination thereof. It should be understood thatranges are contemplated that include multiple sub-ranges presentlydisclosed.

According to some embodiments, at least 95 wt. % of the catalyst may bea combination of the catalytic oxidized metal materials and themesoporous support material. That is, each of the discrete catalystparticles comprises at least 95 wt. %, at least 96 wt. %, at least 97wt. %, at least 98 wt. %, at least 99 wt. %, or at least 99.5 wt. % ofthe combination of catalytic oxidized metal materials and the mesoporoussupport material.

Generally, methods of production may have a significant effect on thefinal characteristics of a catalyst. In some cases, methods ofproduction of the presently disclosed catalyst may affect the locationof catalytic sites, oxidation states of catalytic metals, crystalstructure, and bonds between catalytic materials.

According to one or more embodiments, a method of making a catalyst maycomprise contacting an iron precursor, a copper precursor, and a cobaltprecursor with a mesoporous support material to form an impregnatedsupport material, and calcining the impregnated support material to formthe catalyst. The catalyst may comprise oxidized iron, oxidized cobalt,and oxidized copper, which may be formed from the precursors. In one ormore embodiments, such as depicted in FIG. 1, such a method may includeadditional steps for the preparation of the catalyst, as is subsequentlydescribed.

FIG. 1 depicts a flow chart of one or more embodiments of forming thepresently described catalyst. According to one or more embodiments asdescribed in FIG. 1, the method of making the catalyst may comprise animpregnation solution preparation step 101, a catalyst support materialevacuation step 102, a contacting step 103 where the impregnationsolution may contact the evacuated catalyst support material, a pressurerestoration step 104, an agitation step 105, a drying step 106, and acalcining step 107.

Still referring to FIG. 1, the method may comprise an impregnationsolution preparation step 101. The impregnation solution preparationstep may comprise contacting catalytic precursors with a solvent to forman impregnation solution. The impregnation solution preparation step mayfurther comprise agitating or mixing of the impregnation solution priorto the contacting of the impregnation solution with the mesoporoussupport material. The solvent may be water, or an acid, or a base, or anorganic liquid, or an ionic liquid, or any other substance capable ofdissolving the metal precursors. As is presently described, thecatalytic precursors may include the material of the metal in thecatalyst, such as iron, cobalt, copper, or any combination of these.

In one or more embodiments, the presently disclosed catalysts may beprepared from metal precursors. Generally, the metal precursors (thatis, an iron precursor, a copper precursor, and a cobalt precursor) areconverted to form the metals in the catalyst. For example, metallicportions of the precursor may become the metallic components of thecatalyst and other organic constituents of the precursors may be burnedoff in the catalyst formation process.

In one or more embodiments, the metal precursors may be soluble in thechosen solvent of the precursor solution. One important characteristicof a metal precursor in liquid synthesis procedures, such as the onesdescribed in this disclosure, may be the compatibility of the metalprecursor with the chosen solvent. Without being limited by theory, itis believed that a metal precursor which does not dissolve in a chosensolvent may not achieve sufficient dispersion to effectively coat acatalyst support material.

In one or more embodiments, catalytic precursors may include ironnitrate nonahydrate (Fe(NO₃)₃.9H₂O), copper nitrate trihydrate(Cu(NO₃)₂.3H₂O), and cobalt nitrate hexahydrate (Co(NO₃)₂.6H₂O). Inadditional embodiments, iron precursors may include iron (II) succinate(C₄H₆FeO₄), ferric acetylacetonate (C₁₅H₂₁FeO₆), iron (III) chloride(FeCl₃), iron (II) chloride (FeCl₂), iron (II) acetate (Fe(C₂H₃O₂)₂), orany other suitable iron-containing compound where the elements otherthan iron can be removed by heating or oxidation. In alternateembodiments, copper precursors may include copper (I) acetate(C₂H₃CuO₂), copper (II) sulfate (CuSO₄), copper (II) acetate (C₄H₆CuO₄),bis(acetylacetonate)copper(II) (C₁₀H₁₄CuO₄), or any other suitablecopper-containing compound where the elements other than copper can beremoved by heating or oxidation. In alternate embodiments, cobaltprecursors may include cobalt (II) chloride —CoCl₂, cobalt (II) acetate((CH₃O₂)₂), cobalt acetylacetonate (Co(C₅H₇O₂)₃), or any other cobaltcontaining compound where the elements other than cobalt can be removedby heating or oxidation.

Still referring to FIG. 1, the catalyst support material evacuation step102 may comprise evacuating the mesoporous support material prior to themesoporous support material being contacted with the iron precursor, thecopper precursor, and the cobalt precursor. Still referring to FIG. 1,and without being limited by theory, it is believed that when amesoporous support material is evacuated (step 102), and then contactedwith an impregnation solution (step 103), then undergoes a pressurerestoration step 104, the resulting pressure difference between thepores and the ambient air may help to overcome surface tension and pushthe impregnation solution into the pores. As used in this disclosure,the term evacuation means to hold under a vacuum for a period of time.It should be understood that as used in this disclosure, the term“vacuum” does not only refer to an absolute vacuum, as it also may referto any pressure less than atmospheric pressure, such as an absolutepressure of less than 755 Torr, 700 Torr, 600 Torr, 400 Torr, 100 Torr,10 Torr, 1 Torr, or 0.001 Torr.

According to some embodiments, the evacuation step 102 may compriseholding the mesoporous support material under vacuum, for a duration oftime, at a temperature of, for example, from 80° C. to 90° C., from 90°C. to 100° C., from 100° C. to 110° C., from 110° C. to 120° C., from120° C. to 130° C., or even greater than 130° C., or any combination ofthese ranges. According to some embodiments, the duration of time may befrom 1 minute (min) to 10 minutes (min), from 10 min to 20 min, from 20min to 40 min, from 40 min to 80 min, from 80 min to 160 min, from 160min to 300 min, from 300 min to 600 min, from 600 min to 1200 min, from1200 min to 2400 min, from 2400 min to 4800 min, or greater than 4800min, or any combination of these ranges.

Still referring to FIG. 1, the agitation step 105 may comprise agitatingthe impregnated support material at a temperature of from 40° C. to 80°C., such as from 40° C. to 50° C., from 50° C. to 60° C., from 60° C. to70° C., from 70° C. to 80° C., or any combination thereof. It should beunderstood that the term agitate is intended to mean any action whichcauses increased interactions between molecules within a solution, suchas, but without limitation, stirring, sonication, shaking, mixing, andthe like. According to one or more embodiments, agitation of the supportmaterial occurs for 3 hours at a temperature of 60° C., from 40° C. to50° C., from 50° C. to 60° C., from 60° C. to 70° C., from 70° C. to 80°C., or any combination thereof.

According to described embodiments, the impregnation of the mesoporoussupport material may comprise contacting the mesoporous support materialwith a solution comprising one or more metal catalyst precursors. Forexample, the support material may be submerged in the solutioncomprising the one or more metal catalyst precursors, an impregnationmethod sometimes referred to as a saturated impregnation. In embodimentsof saturated impregnation, the support may be submerged in an amount ofsolution comprising the metal catalyst precursors 2 to 4 times of thatwhich is absorbed by the support, and the remaining solution issubsequently removed. According to another embodiment, the impregnationmay be by incipient wetness impregnation, sometimes referred to ascapillary impregnation or dry impregnation. In embodiments of incipientwetness impregnation, the metal catalyst precursor containing solutionis contacted with the support, where the amount of solution isapproximately equal to the pore volume of the support and capillaryaction may draw the solution into the pores.

Referring again to FIG. 1, the method may comprise a drying step 106that may include drying the impregnated support material. The drying maybe under vacuum at a temperature of from 80° C. to 150° C. According toone or more embodiments, drying the impregnated support material mayoccur under a vacuum at a temperature of from 80° C. to 90° C., from 90°C. to 100° C., from 100° C. to 110° C., from 110° C. to 120° C., from120° C. to 150° C., or any combination thereof. It should be understoodthat ranges are contemplated that include multiple sub-ranges presentlydisclosed.

Still referring to FIG. 1, the method may further comprise a calciningstep 107 that may comprise heating the impregnated support material at atemperature greater than 450° C. Generally, the International Union ofPure and Applied Chemistry (IUPAC) defines calcining or calcination as aprocess of heating to relatively great temperatures in air or oxygen.However, calcination may also refer to thermal treatment in the absenceor partial absence of oxygen with the intent to bring about thermaldecomposition. According to some embodiments, after the contacting ofthe support material with the solution, the support material may becalcined at a temperature of at least 450° C., or at least 500° C.,(such as from 500° C. to 600° C.) for a time of at least 3 hours (suchas 3 hours to 6 hours). For example, the calcining may be at atemperature of 550° C. for 4 hours. Generally, the impregnation processwill allow for attachment of the metal catalyst onto the supportmaterials (that is, the zeolite and metal oxide support). The metalcatalyst precursors may include one or more of iron (Fe), copper (Cu),cobalt (Co), and following the impregnation, are present on the catalystsupport as compounds comprising Fe, Cu, Co, or combinations thereof.While these metal catalyst materials may include metal oxides, it shouldbe appreciated that the metal catalyst materials are distinct from themesoporous support material of the catalyst which may, in someembodiments, be alumina.

In one or more embodiments, the presently disclosed catalysts may havegood catalytic functionality for converting polystyrene intoethylbenzene. Generally, polystyrene is one of the most widely producedand used polymers, made up of repeating styrene monomers. Polystyrenehas a relatively great energy density but is usually not recycled. It isbelieved that industry may desire a method to convert polystyrene tomore active constituent chemicals, such as ethylbenzene. According toone or more embodiments, a method of catalytically convertingpolystyrene may comprise contacting polystyrene with a catalyst to forma product which may comprise ethylbenzene, where the catalyst maycomprise oxidized iron. According to one or more additional embodiments,a method of catalytically converting polystyrene may comprise contactinga feed stream comprising polystyrene with a catalyst to form a productstream comprising ethylbenzene.

According to one or more embodiments, the feed stream that is convertedby contact with the catalyst may comprise at least 50 wt. % polystyrene,such as at least 50 wt. % polystyrene, at least 60 wt. % polystyrene, atleast 70 wt. % polystyrene, at least 80 wt. % polystyrene, at least 90wt. % polystyrene, at least 95 wt. % polystyrene, or even at least 99wt. % polystyrene. The feed stream may comprise a liquid, a solid, acolloid, or any other chemical state. For example the feed stream maycomprise polystyrene particles, polystyrene floating on water,polystyrene mixed with acetone, melted polystyrene, or any combinationthereof.

According to one or more embodiments, the polystyrene may be in a liquidphase when contacted with the catalyst. It should be understood that thepolystyrene need not be in a solid phase when first contacted with thecatalyst and that it may be converted to a liquid phase while in contactwith the catalyst. For example, solid polystyrene may be introduced tothe catalyst at 25° C. and the temperature may be raised to 250° C.,where the now liquid polystyrene may contact with the catalyst.

According to one or more embodiments, the polystyrene may be contactedwith the catalyst in an atmosphere comprising one or more of oxygen, aninert gas, or a reducing gas. For example the polystyrene may becontacted with the catalyst in an atmosphere comprising air or thepolystyrene may be contacted with the catalyst in an atmosphere enrichedin one or more constituents relative to air. Without being limited byany particular theory, it is believed that increasing concentrations ofhydrogen may increase reaction rates. According to one or moreembodiments, the polystyrene may be contacted with the catalyst in anatmosphere which comprises greater than 1 mole percent (mol. %)hydrogen, greater than 5 mol. % hydrogen, greater than 10 mol. %hydrogen, greater than 25 mol. % hydrogen, greater than 50 mol. %hydrogen, greater than 75 mol. % hydrogen, greater than 90 mol. %hydrogen, or even greater than 99 mol. % hydrogen. Without being limitedby any particular theory, it is believed that sufficient hydrogen may bereleased from cracking of the polystyrene and that selectivity may beimproved by not having additional hydrogen. According to someembodiments, the atmosphere may comprise less than 1 mol. % oxygen orfrom 1 mol. % to 5 mol. % oxygen, from 5 mol. % to 15 mol. % oxygen,from 15 mol. % to 20 mol. % oxygen, from 20 mol. % oxygen to 22 mol. %oxygen, from 22 mol. % oxygen to 30 mol. % oxygen, from 30 mol. % oxygento 40 mol. % oxygen, from 40 mol. % oxygen to 50 mol. % oxygen, from 50mol. % oxygen to 75 mol. % oxygen, from 75 mol. % oxygen to 90 mol. %oxygen, from 90 mol. % oxygen to 95 mol. % oxygen, from 95 mol. % oxygento 99 mol. % oxygen, or any combination thereof.

According to some embodiments, the polystyrene may be contacted with thecatalyst at a temperature of less than 350° C. while still maintainingrelatively good catalytic conversion performance. For example, thepolystyrene may be contacted with the catalyst at a temperature of lessthan 350° C., or less than 325° C., less than 300° C., less than 275°C., or less than 250° C. According to some embodiments, the polystyrenemay be contacted with the catalyst at a temperature of from 100° C. to125° C., from 125° C. and 150° C., from 150° C. and 175° C., from 175°C. and 200° C., from 200° C. and 225° C., from 225° C. and 240° C., from240° C. and 260° C., from 260° C. and 275° C., from 275° C. and 300° C.,from 300° C. and 325° C., from 325° C. and 350° C., or any combinationthereof. It should be understood that the polystyrene may contact thecatalyst at a temperature less than this range and the temperature maybe increased until it falls within this range. For example, in someembodiments, the polystyrene may contact the catalyst at a temperatureof 25° C. and the temperature may be increased to 250° C. at apredetermined rate.

According to some embodiments, the polystyrene may contact the catalystwithin one of a fluidized bed reactor, a continuous stirred tankreactor, a batch reactor, a stirred tank reactor, a slurry reactor, or amoving bed reactor. According to some embodiments, the polystyrene maycontact the catalyst within any reactor suitable for heterogeneouschemical reactions. It should be understood that the polystyrene neednot first contact the catalyst within the reactor. For example, in someembodiments, the polystyrene may contact the catalyst in a feed pipe andthen both the polystyrene and the catalyst may be in contact within thereactor.

According to some embodiments, the product comprising ethylbenzene maycomprise a liquid phase and a solid phase. According to someembodiments, the weight ratio of the liquid phase to the solid phase maybe at least 2:1 at 25° C. For example the weight ratio of the liquidphase to the solid phase at 25° C. may be at least 2:1, at least 3:1, atleast 4:1, at least 5:1, at least 6:1, at least 7:1, at least 8:1, atleast 9:1, at least 10:1, at least 11:1, or any combination thereof. Thesolid phase may comprise unreacted polystyrene, crosslinked styrenematerial, solid catalyst material, and char. The liquid phase maycomprise ethylbenzene, solvent, toluene, styrene, cumene,alpha-methylstyrene, and dimers. It should be understood that theproducts may be formed at a greater temperature than 25° C., such as250° C., where more of the product may be a gas. For example the productethylbenzene has a boiling point of 136° C. and may therefore be a gasat the reaction conditions but a liquid at 25° C.

According to some embodiments, the product stream may comprise a liquidsfraction at 25° C. The liquid fraction may comprise at least 25 wt. % ofthe carbon material in the original polystyrene. For example, the liquidfraction may comprise at least 25 wt. %, at least 50 wt. %, at least 75wt. %, at least 80 wt. %, at least 85 wt. %, at least 90 wt. %, at least95 wt. %, or even at least 90 wt. % of the carbon material in theoriginal polystyrene. The liquids fraction may comprise ethylbenzene,solvent, toluene, styrene, cumene, alpha-methylstyrene, and dimers.

According to some embodiments, the liquid phase of the product streammay be greater than 60 mol. % ethylbenzene. For example, the liquidphase may be greater than 60 mol. % ethylbenzene, greater than 70 mol. %ethylbenzene, greater than 80 mol. % ethylbenzene, or even, greater than90 mol. % ethylbenzene. It should be understood that the presentlydisclosed ratios may be taken at 25° C. because ethylbenzene may be agas at temperatures greater than 136° C.

In one or more embodiments, the presently disclosed catalysts may beutilized to crack petroleum hydrocarbons such as, without limitation,tars. According to one or more embodiments, a method of catalyticallycracking a petroleum hydrocarbon may comprise contacting the petroleumhydrocarbon feed with the presently disclosed catalyst to form upgradedpetroleum hydrocarbons. As presently described, the contacting of thepetroleum hydrocarbon by the catalyst forms an “upgraded petroleumhydrocarbon” which may have one or more of reduced density (greater APIgravity), reduced viscosity, or reduced average molecular weight.Generally, the upgraded petroleum hydrocarbons are greater in value thanthe pre-processed petroleum hydrocarbons that have not been contactedwith the catalyst.

As presently described, “petroleum hydrocarbons” may refer to chemicalcompositions that comprise oil such as crude petroleum materials and/orproducts refined from petroleum oils, such as gasoline and diesel. Forexample, petroleum hydrocarbons may include liquid crude oils, tarsands, residuals from crude oil refining, and middle distillates fromcrude oil refining. It is contemplated that the petroleum hydrocarbonswhich may be cracked by the presently disclosed catalyst may be in afeed stream that includes at least 50 weight percent wt. %, at least 75wt. %, at least 95 wt. %, or even at least 99 wt. % of the respective,disclosed types of petroleum hydrocarbons.

According to some embodiments, the petroleum hydrocarbon feed may havean American Petroleum Institute (API) gravity of less than or equal to40 degrees (°). According to some embodiments, the petroleum hydrocarbonmay have an API gravity of less than or equal to 35 degrees, 30 degrees,22.3 degrees, 20 degrees, 10 degrees, 8 degrees, 6 degrees, or even 4degrees. Generally, API gravity is a measure of how heavy or light apetroleum liquid is compared to water.

According to one or more embodiments, the petroleum hydrocarbons thatare processed may include tar such as tar sands, also known asbituminous sands or oil sands. Generally, tar sands are defined asreservoirs containing oil too viscous to flow in sufficient quantitiesfor economic production. While tar sands may have a relatively lessereconomic value, their economic value may be increased though catalyticupgrading as presently described.

In one or more embodiments, the petroleum hydrocarbon feed may comprisecrude oil. As used in this disclosure, crude oil may be a mixture ofdifferent hydrocarbons. The crude oil may be unprocessed or it may bepre-processed for removal of undesirable materials such as sulfur, heavymetals, nitrogen, and other like contaminants. Generally crude oil maycontain light distillates, middle distillates, and residue. The middledistillates and residue may be catalytically cracked or converted intomore valuable components. According to some embodiments, the petroleumhydrocarbon feed may comprise middle distillates or residue or both.Middle distillates may include hydrocarbons having a boiling pointbetween 200° C. and 300° C. Residues may include hydrocarbons having aboiling point greater than 300° C.

According to some embodiments, the petroleum hydrocarbons of the feedmay have a viscosity greater than 100 centipoises at reservoirtemperature. For example the petroleum hydrocarbon may have a viscositygreater than 100 centipoises, greater than 500 centipoises, greater than1,000 centipoises, greater than 2,000 centipoises, greater than 5,000centipoises, greater than 10,000 centipoises, or even greater than15,000 centipoises, at reservoir temperature, or any combinationthereof. It should be understood that viscosity may be a function oftemperature and as such viscosity measurements may be taken at a definedtemperature. Reservoir temperature is understood to mean the undisturbedtemperature in the reservoir. For example if a reservoir were 50° C.before drilling and superheated steam were used to raise the averagereservoir temperature to 90° C., the viscosity at 50° C. should be usedfor this measurement.

According to one or more embodiments, the petroleum hydrocarbons may becontacted with the catalyst at a temperature of from 100° C. to 1000° C.For example the petroleum hydrocarbons may be contacted with thecatalyst at a temperature of from 100° C. to 200° C., from 200° C. to300° C., from 300° C. to 400° C., from 400° C. to 500° C., from 500° C.to 600° C., from 600° C. to 700° C., from 700° C. to 800° C., from 800°C. to 900° C., from 900° C. to 1000° C., or any combination thereof. Itshould be understood that ranges are contemplated which include multiplesub-ranges presently disclosed.

According to one or more embodiments, the upgraded petroleum hydrocarbon(which may be all or a portion of a product stream) may have an APIgravity of at least 1 degree greater than the petroleum hydrocarbonfeed. For example, the product stream may have an API gravity of 1degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 10 degrees, 15degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees,greater than the petroleum hydrocarbon feed in its pre-cracked state.

In one or more embodiments, the presently disclosed catalysts may beutilized for cracking of petrochemical crude feedstocks in asubterranean environment. According to one or more embodiments, a methodfor reducing the viscosity of a subterranean petroleum hydrocarbon maycomprise heating a subterranean petroleum hydrocarbon within a petroleumhydrocarbon reservoir and contacting the heated subterranean petroleumhydrocarbon with a catalyst to reduce the viscosity of the subterraneanpetroleum hydrocarbon. It should be understood that both the heatingstep and the contacting steps may be carried out underground. As used inthis disclosure, a petroleum hydrocarbon reservoir refers to anunderground deposit of petroleum hydrocarbons, such as tar.

According to one or more embodiments, the method may further compriseigniting a subterranean combustion zone within the petroleum hydrocarbonreservoir. As used in this disclosure, a subterranean combustion zonerefers to any underground area of sustained combustion of petroleumhydrocarbons. For example, according to some embodiments, thesubterranean combustion zone may comprise fire flooding. Generally, fireflooding is a method of thermal recovery in which a flame front isgenerated in the reservoir by igniting a fire at the sandface of aninjection well. Generally, the sandface of an injection well may referto the interface between the reservoir and the well. Injection of oxygencontaining gasses may then be used to help maintain the flame front.Without being limited by any particular theory, it is believed that theresultant, steam, heat, and pressure from the flame front may driveheavy oil to the production wells. It is believed that the heat maycause some degree of thermally induced cracking but further upgradingmay still be desired by industry.

According to some embodiments, the catalyst and a production well arestructurally configured such that the heated petroleum hydrocarbons maycontact a catalyst within a production well. As used in this disclosure,a production well is a device which may be used to remove petroleumhydrocarbons from a petroleum hydrocarbon reservoir. Generally, thecatalyst may form a packing within the production well. The catalyst maybe granular, porous, or formed into shapes such a Rasching rings, Berlsaddles, Intalox saddles, or any other shape capable of promoting solidto liquid contact. Without being limited by theory, it is believed thatthe useful lifetime of a catalyst bed may be extended when the reactionoccurs in a plug flow configuration. In such a configuration, the rateof catalyst inactivation may differ along the length of the pipe,constantly exposing new sections of catalyst to unreacted heavy oil.

According to some embodiments the catalyst and a production well arestructurally configured such that the heated petroleum hydrocarbons maycontact the catalyst as the heated petroleum hydrocarbons enter theproduction well. For example, the catalyst bed may constitute an annulusaround the production well. The annulus may be within the productionwell or the annulus may be around the exterior of the production well.Heated petroleum hydrocarbons may enter the production well atperforated intervals and the heated petroleum hydrocarbons may contactthe catalyst at these perforated intervals, either inside or outside ofthe production well.

According to some embodiments, the catalyst may be dispersed within agravel pack surrounding a production well. Generally a gravel pack mayinclude gravel of a specific size placed around a production well.Without being limited by theory, it has been shown that the dispersal ofa catalyst around a production well may yield similar results to packingwithin the production well while eliminating some technical barriers.Improved dispersion may yield relatively greater catalyst utilizationrates and increased space for catalyst may help to offset catalystdeactivation.

The presently described processes may be useful for the catalyticcracking of petroleum hydrocarbons, both underground in an oil formationor in a refinery. For example, when the cracking is performedunderground, it may be particularly useful for reducing the viscosity oftars so that they may be more easily and cost-efficiently transported tothe surface. In other embodiments, the presently described catalysts maybe used in refining operations and coupled with one or more refiningprocesses for forming desired products from crude oils. These processesmay have advantages such as relatively lesser operating temperature,relatively increased operating lifetimes, and relatively greaterconversion rates compared with conventional cracking catalysts.

EXAMPLES

Using the embodiments of the present disclosure, catalyst systems wereproduced which exemplify the catalytic attributes presently described.It should be understood that the ensuing Examples are illustrative ofone or more embodiments presently disclosed, and should not be construedin any way as limiting on the appended claims or other portions of thepresent application. It should be understood that in the followingexamples, references to Fe, Cu, and Co may refer to oxidized iron,oxidized copper, and oxidized cobalt respectively; for example,FeCuCo/alumina may refer to oxidized iron, oxidized copper, and oxidizedcobalt, all supported on alumina where the FeCuCo comprises threeseparate oxide compounds, or oxide compounds with two or more of Fe, Cu,or Co.

Example 1—Preparation of Fe—Cu—Co/alumina

To prepare a sample of the 1 weight percent (wt. %) multi-metalliccatalyst, 5.0 grams (g) of gamma-alumina was evacuated overnight.Fe(NO₃)₃.9H₂O, Cu(NO₃)₂.3H₂O, and Co(NO₃)₂.6H₂O were measured and mixedwith deionized water to form an impregnation solution. The evacuatedgamma-alumina was sonicated for 10 minutes, then the impregnationsolution was added to the alumina in a quantity slightly greater thanthe alumina pore volume. The resulting mixture was then stirred at 60°C. for 3 hours, then dried in a vacuum oven overnight at 110° C.Finally, the dried FeCuCo/Al₂O₃ was calcined at 550° C. for 4 hours (hr)in air.

Table 1 gives a comparison of the raw alumina support used in Example 1and the prepared FeCuCo/Alumina catalyst of Example 1. It can be seenthat the BET surface area and the pore volume both decreased afterimpregnation of the support although the pore size did not change. Thisis believed to indicate that the pore structure remained constant whilesome of the pores became filled with oxidized metals.

TABLE 1 BET Surface Pore Pore Volume Area Size (centimeters cubedCatalyst (m²/g) (nm) per gram (cm³/g)) Raw Alumina Support 256.31 13.160.84 FeCuCo/Alumina 208.90 12.13 0.64

FIG. 2A gives the nitrogen adsorption-desorption isotherm of the aluminacatalyst support 201 and the FeCuCo/alumina catalyst 202 of Example 1.The pattern of type IV hysteresis shown in hysteresis loops 203(alumina) and 204 (FeCuCo/alumina) indicate that the nitrogen is beingadsorbed onto a mesoporous solid via multilayer adsorption followed bycapillary condensation.

FIG. 2B gives the pore size distribution of the alumina catalyst support211 and the FeCuCo/alumina catalyst 212. Both samples have peak poresize concentrations centered around 100 angstroms, shown at 213(alumina) and 214 (FeCuCo/alumina). Generally, CO₂ temperatureprogrammed desorption (TPD) can be used to determine bascicity of asolid. FIG. 3A shows the CO₂ TPD for the raw alumina used in Example 1and the FeCuCo/alumina catalyst formed in Example 1. Both the aluminaand the FeCuCo/alumina curves show a peak at 301 roughly consistent insize. The synthesis procedure in Example 1 appears to remove the peak at303 and creates a new medium strength basicity peak 302 around 400° C.Generally, NH₃ temperature programmed desorption (TPD) can be used todetermine the acidity of a solid. FIG. 3B shows the NH₃ TPD curves forthe raw alumina 312 used in Example 1 and the FeCuCo/alumina catalyst311 formed in Example 1. The change in intensity after the addition ofFeCuCo to the alumina support indicates an increase in acidity. It isbelieved that the increase in acidity is due to the Lewis acidity ofiron.

FIG. 4A shows the X-ray diffraction (XRD) pattern of the parent aluminumoxide and FIG. 4B shows the XRD pattern of the FeCuCo/alumina catalyst.There is no significant difference between the XRD pattern of the FIGS.4A and 4B. This is believed to suggest good dispersion of the Fe—Cu—Coon the alumina support. The diffraction peaks appear at 19.8°, 32°,37.1°, 39.4°, 45.9°, 61.1° and 66.8° which corresponds to (111), (220),(331), (222), (400), (511) and (440) which matches the gamma-Al2O3XRDpattern.

Example 2—Conversion of Polystyrene to Ethylbenzene

To convert polystyrene to ethylbenzene, 2.0 g of polystyrene werecombined with from 200 mg and 500 mg of the catalyst from Example 1, ina 25 mL reaction vessel. The resulting mixture was stirred and heatedunder air at a ramp rate of 4° C./min to a final temperature of 250° C.and held at 250° C. for 90 minutes. The Comparative Example data ofTable 2 is supplied from Kijenski, J. and T. Kaczorek, Catalyticdegradation of polystyrene. Polimery, 2005, 50(1):p. 60-63.

TABLE 2 Liquid Rxn Temp Catalyst Yield % (° C.) Atmosphere ComparativeNickel 70 375 Hydrogen Example A molybdenum (H₂) alumina (NiMo/Al₂O₃)Comparative NiMo/Al₂O₃ 70.9 400 Nitrogen Example B (N₂) ComparativeCobalt 77.3 375 H₂ Example C molybdenum alumina (CoMo/Al₂O₃) ComparativeCoMo/Al₂O₃ 72.6 400 N₂ Example D Comparative Iron cobalt 80.5 375 H₂Example E silica (FeCo/SiO₂) Comparative FeCo/SiO₂ 71.9 400 N₂ Example FExample 2 FeCuCo/Al₂O₃ 90 250 Air

Referring now to Table 2, it can be seen that only the presentdisclosure provides the desired combination of relatively greater liquidyield and relatively lesser reaction temperature for the catalyticdegradation of polystyrene.

FIG. 5A shows the relationship between catalyst loading and liquidyields for the reaction of Example 2. 501, 503, 505, and 507 show theliquid yield percentages for a catalyst loading of 200 milligrams (mg),300 mg, 400 mg, and 500 mg, respectively. 502, 504, 506, and 508, showthe liquid yield percentages for a catalyst loading of 200 mg, 300 mg,400 mg, and 500 mg, respectively.

FIG. 5B shows the relationship between catalyst loading and theconstituents of the liquid products. In all cases the yield ofethylbenzene is equal to or greater than 80%. 521, 531, 541, and 551show the yield of styrene for a catalyst loading of 200 mg, 300 mg, 400mg, and 500 mg, respectively. 522, 532, 552, and 552 show the yield ofcumene for a catalyst loading of 200 mg, 300 mg, 400 mg, and 500 mg,respectively. 523, 533, 543, and 553 show the yield ofalpha-methystyrene for a catalyst loading of 200 mg, 300 mg, 400 mg, and500 mg, respectively. 524, 534, 544, and 554 show the yield of toluenefor a catalyst loading of 200 mg, 300 mg, 400 mg, and 500 mg,respectively. 525, 535, 545, and 555 show the yield of ethylbenzene fora catalyst loading of 200 mg, 300 mg, 400 mg, and 500 mg, respectively.

FIG. 6A shows a scanning electron microscope (SEM) image of theFeCuCo/alumina catalyst of Example 1. This figure shows the lack ofmetal clusters indicating homogenous distribution of the oxidized iron,oxidized cobalt, and oxidized copper within the support. FIG. 6B shows aSEM image of the FeCuCo/alumina catalyst of Example 1 after the processof Example 2. The white dots 601 in this figure are believed to be metalclusters which have aggregated during the reaction.

FIG. 7A shows a scanning transmission electron microscope (STEM) imageof the catalyst of Example 1. The catalyst appears to have a nest likestructure which was not disturbed by the reaction as shown in FIG. 7B.FIG. 7B shows a STEM image of the spent catalyst of Example 2.

FIG. 8A shows scanning transmission electron microscope-energydispersive spectroscopy (STEM-EDS) of the FeCuCo/alumina of Example 1.FIG. 8B shows STEM-EDS signals of spent FeCuCo/alumina from Example 2.FIG. 8C shows scanning transmission electron microscope-electron energyloss spectroscopy (STEM-EELS) of the FeCuCo/Alumina of Example 1. FIG.8D shows STEM-EELS of spent FeCuCo/alumina from Example 2.

For the purposes of describing and defining the present subject matter,it is noted that reference to a characteristic of the subject matter ofthe present disclosure being a “function of” a parameter, variable, orother characteristic is not intended to denote that the characteristicis exclusively a function of the listed parameter, variable, orcharacteristic. Rather, reference to a characteristic that is a“function” of a listed parameter, variable, etc., is intended to be openended such that the characteristic may be a function of a singleparameter, variable, etc., or a plurality of parameters, variables, etc.

It is also noted that recitations in this disclosure of “at least one”component, element, etc., should not be used to create an inference thatthe alternative use of the articles “a” or “an” should be limited to asingle component, element, etc.

It is noted that recitations of a component of the present disclosurebeing “configured” in a particular way, to embody a particular property,or to function in a particular manner, are structural recitations, asopposed to recitations of intended use. More specifically, thereferences to the manner in which a component is “configured” denotes anexisting physical condition of the component and, as such, is to betaken as a definite recitation of the structural characteristics of thecomponent.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments thereof, it is noted that thevarious details presently disclosed should not be taken to imply thatthese details relate to elements that are essential components of thevarious embodiments presently described, even in cases where aparticular element is illustrated in each of the drawings that accompanythe present description. Further, it will be apparent that modificationsand variations are possible without departing from the scope of thepresent disclosure, including, but not limited to, embodiments definedin the appended claims. More specifically, although some aspects of thepresent disclosure are presently identified as preferred or particularlyadvantageous, it is contemplated that the present disclosure is notnecessarily limited to these aspects.

It is noted that one or more of the following claims utilize the term“where” as a transitional phrase. For the purposes of defining thepresent subject matter, it is noted that this term is introduced in theclaims as an open-ended transitional phrase that is used to introduce arecitation of a series of characteristics of the structure and should beinterpreted in like manner as the more commonly used open-ended preambleterm “comprising.”

The invention claimed is:
 1. A method of catalytically convertingpolystyrene, the method comprising: contacting polystyrene with acatalyst to form a product comprising ethylbenzene, where the catalystcomprises: catalytic oxidized metal materials comprising: oxidized iron;oxidized cobalt; and oxidized copper; and a mesoporous support materialcomprising pores having an average pore diameter of from 2 nm to 50 nm,wherein a weight ratio of iron atoms:cobalt atoms:copper atoms in thecatalyst is 1:0.4-0.6:0.5-0.7.
 2. The method of claim 1, where thepolystyrene is in a liquid phase when contacted with the catalyst. 3.The method of claim 1, where the polystyrene is contacted with thecatalyst in an atmosphere comprising one or more of oxygen, an inertgas, or a reducing gas.
 4. The method of claim 1, where: the productcomprising ethylbenzene comprises a liquid phase and a solid phase; anda weight ratio of liquid phase to solid phase is at least 2:1 at 25° C.5. The method of claim 4, where the liquid phase comprises greater than60 mole percent ethylbenzene.
 6. The method of claim 1, where thepolystyrene contacts the catalyst within one of a fluidized bed reactor,a continuous stirred tank reactor, a batch reactor, a stirred tankreactor, a slurry reactor, or a moving bed reactor.
 7. The method ofclaim 1, where the mesoporous support material comprises aluminamaterial or silica material.
 8. The method of claim 1, where themesoporous support material comprises gamma alumina.
 9. The method ofclaim 1, where at least 95 wt. % of the catalytic oxidized metalmaterials are a combination of the oxidized iron, the oxidized cobalt,and the oxidized copper.
 10. The method of claim 1, where at least 95wt. % of the mesoporous support material comprises alumina.
 11. Themethod of claim 1, where at least 95 wt. % of the catalyst is acombination of the catalytic oxidized metal materials and the mesoporoussupport material.
 12. A method of catalytically converting polystyrene,the method comprising: contacting a feed stream comprising polystyrenewith a catalyst to form a product stream comprising ethylbenzene, wherethe catalyst comprises: catalytic oxidized metal materials comprising:oxidized iron; oxidized cobalt; and oxidized copper; and a mesoporoussupport material comprising pores having an average pore diameter offrom 2 nm to 50 nm, wherein a weight ratio of iron atoms:cobaltatoms:copper atoms in the catalyst is 1:0.4-0.6:0.5-0.7.
 13. The methodof claim 12, where the feed stream comprises at least 50 wt. % ofpolystyrene.
 14. The method of claim 12, where the product streamcomprises a liquids fraction at 25° C.
 15. The method of claim 12, wherethe liquids fraction comprises at least 60 mole percent ethylbenzene.16. The method of claim 12, where: the mesoporous support materialcomprises alumina material.
 17. The method of claim 12, where at least95 wt. % of the catalytic oxidized metal materials are a combination ofthe oxidized iron, the oxidized cobalt, and the oxidized copper.
 18. Themethod of claim 12, where at least 95 wt. % of the mesoporous supportmaterial comprises alumina.
 19. The method of claim 1, where thepolystyrene is contacted with the catalyst at a temperature of less than350° C.
 20. The method of claim 12, where the feed stream is contactedwith the catalyst at a temperature of less than 350° C.